Depending on the processed material from each drill must be properly sharpened. To verify the correct angle will help a specially prepared square plate of copper or aluminium with a thickness of 1 mm.
To become operational protractor enough to cut it cut, as shown in the picture: a large cutout at an angle of 120 degrees, the other half is 60 degrees and the surviving corner of a square is 90.
Recommend to read
NECROLATRY TABLE
"If I get sick — go to the doctors won't; turn to friends..." — wrote the poet J. Smelyakov. But life shows that you have to apply to doctors and friends, because without their help, it...
ON THE EVE OF PEARL HARBOR
By the end of the First world war the Navy of the United States of America was large, but very strange composition: a significant linear force, the almost complete lack of any modern...
